Building for explosive dangerous materials

ABSTRACT

The invention relates to a new construction for a confined space such as a building for containing dangerous explosive material, for instance a building adapted to be used in connection with the production, handling and/or storing of explosives, ammunition or other explosive goods. The walls of the building comprises an internal and an external cylindrical shell construction with upwardly open cylindrical shells, the spacing therebetween being filled with sand. The shells are attached to a circular floor- or bottom plate. The roof construction of the building comprises a web structure anchored to the internal cylindrical shell and on top of which web structure is positioned a cover which preferably should be of resolved or defibrated material. On top of the cover is positioned a layer of sand, and finally a roof covering on top of the sand layer.

United States Patent 1191 Hiorth BUILDING FOR EXPLOSIVE DANGEROUS MATERIALS Inventor: Hans Hiorth, Lierbyen, Norway Assignee: Dyno Industrier A.S., Oslo, Norway Filed: Feb. 13, 1973 Appl. No; 332,164

Foreign Application Priority Data Feb. 17, 1972 Norway 476/72 US. Cl 109/1 R, 52/249, 109/78 Int. Cl. E05g 3/00, E04b l/32 Field of Search 109/1 R, l B, 2, 80, 82,

I References Cited i UNITED STATES PATENTS 6/1902 Nelson 109/49.5 X 9/1923 Smith et al.... 11/1924 2/1963 6/1970 .Nelson 52/249 X y 1111 3,832,958 Sept. 3, 1974 3,552,330 1/1971 Youmans 52/204 Primary Examiner-Dennis L. Taylor Attorney, Agent, or FirmWenderoth,. Lind & Ponack 5 7 ABSTRACT The invention relates to a new construction for a confined space such as a building for containing dangerous explosive material, for instance a building adapted to be used in connection with the production, handling and/or storing of explosives, ammunition or other explosive goods. The walls of the building comprises an internal and an external cylindrical shell construction with upwardly open cylindrical shells, the

spacing therebetween being filled with sand. The shells are attached to a circular flooror bottom plate. The roof construction of the building comprises a web structure anchored to the internal cylindrical shell and on top of which web structure is positioned a' cover which preferably should be of resolved or defibrated material. On top of the cover is positioned a layer of sand, and finally a roof covering on top of the sand layer.

15 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to a new construction for a confined space such as a building for containing dangerous explosive material, for instance a building adapted to be used in connection with the production, handling and/or storing of explosives, ammunition or other explosive goods.

It is desirable to make a such building in a way such that the building as such by an accidental internal explosion shall result in the least possible damage outside the building in consequence of pressure waves and thrown building parts etc. Simultaneously it is desirable that the building itself be sufficiently strong to withstand influences from the outside, for instance from explosive pressure waves, thrown pieces of goods, etc., which for instance could arrive from an explosion in the vicinity.

PRIOR ART Hitherto one has sought to fulfill these partially opposing requirements by making the building of light and fragile materials, since it was pre-supposed that the building should be totally destroyed. In order to protect adjacent buildings and the like it was customary to locate sand or soil dikes around the building, in order to lead the detonation pressure waves and parts of the disintegrated building in an upward direction and thereby to have a baffling or shielding effect against the neighbourhood.

In order to obtain an acceptable degree of safety, the beforementioned building system had to be designed with great mutual distances between the buildings which, however, is objectionable for effective production of explosives, since production of explosives should take place in a number of separate buildings positioned one after the other. Thus this known system requires a very large ground area.

In modern production methods for making explosives, particularly in connection with comparatively small explosive quantities, it is known to make the stem or main part of the building very strong, but having one wall or the roof structure thereof of a very light and fragile construction with the aim that the detonation pressure wave shall blow out the weak part of the building and thereby relieve the remainder of the construction..

For buildings working with relatively large quantities of explosives this principle has been further developed by positioning sand dikes against strong walls, and making the roof structure as a light and not fixedly connected construction, thus designed to be blown upwards. Also, a sand layer may be positioned on the roof structure in order to dampen the blowing effect. In such buildings the static pressure due to the sand body will be'so great that the building must be constructed with concrete walls in order to withstand the sand pressure, and one must arrange strong beams in the roof structure, preferably laminated wooden beams, to support the sand layer.

Trial detonations of large quantities of explosives in such buildings have shown that the concrete walls are fractured into larger and smaller pieces which have been thrown outwards together with the roof beam structure which by incomplete defibration likewise will form dangerous thrown pieces. It is particularly the upper part of the building which is thrown out, and many of the fragments from the building and from equipment therein, etc., willattain a low ballistic angle, a situation which contributes to a distribution of objects over a large area.

OBJECTS OF THE INVENTION The main object of the present invention is to provide a building construction by which an internal explosion results in no dangerous thrown pieces from the building itself. The construction should furthermore be such that fragments from equipment and the like in the building and which hit the walls, are caught up in the walls.

A further object is to provide a building construction which results in that fragments and the like which by an internal explosion strike the roof structure, are caught up therein and guided vertically upwards together with the sand layer which as a pre-condition constitutes the substantial part of the blowable or escapable part of the roof structure.

THE INVENTION In accordance with the invention these and other objects are assumed fulfilled by providing that the walls of the building comprise an internal and an external cylindrical shell construction with upwardly open cylindrical shells, the spacing therebetween being filled with sand. The shells are attached to a circular floor or bottom plate. The roof construction of the building comprises a web structure anchored to the internal cylindrical shell and on top of which web structure is positioned a cover which preferably should be of resolved or defibrated material. On top of the cover is positioned a layer of sand, and finally a roof covering on top of the sand layer.

In a preferred embodiment of the invention the building has a frame or core of steel and comprises two concentric, cylindrical steel shells which are welded to a circular bottom plate of steel, and at a distance below the upper edge of the inner shell is provided anchoring means for the supporting web structure for the roof.

The building construction in accordance with the invention is particularly economically attractive for explosive concentrations corresponding to less than 6 kilos TNT per m building space below the web structure, and the steel structure should be calculated on this basis such that it is not loaded beyond its dynamic tensile or break strength. One should thus select a steel quality which satisfies the shock resistance shearing strength test for the selected plate gage, temperature and velocity of detonation.

At an explosion in for instance an apparatus or in a machine located in such a building, metal pieces from the goods thereof adjacent the explosives will be shot outwards against the wall construction with a velocity exceeding several hundred meters per second. Fragments will in a large degree break through the internal shell, but will thereafter be efiectively slowed down in the sand between the shells and will stop entirely before the outer shell is reached.

In connection with the roof structure is utilized a previously known principle whereby high strength beams fixed by welding and which have a large height/width ratio and which thus possess a small surface against the detonation pressure and which therfore normally will 3 remain intact during the explosion, simultaneously as the explosive gasses are allowed to escape between the beams and throw up the cover and the layer of sand. The roof structure in accordance with the present invention involves a further developement of this principle.

In a preferred embodiment of the invention the supporting web structure of the roof structure has such a design that it does not prevent radial deformations of the wall construction.

Pieces of goods from the source of explosion which move against the roof will, due to the very high initial velocity, penetrate into the sand layer before the sand is able to leave the building. Thereby these pieces will be slowed down and more or less be guided by the sand mass in a direction vertically upwards.

BRIEF DESCRIPTION OF THE DRAWINGS 'FIG. I,

FIG. 3 is a horizontal sectional view similar to FIG. 2, but which illustrates a preferred embodiment for the web structure in the roof construction.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION In the drawings the reference number I designates the common bottom plate for the two cylindrical shells 2 and 3. A so-called cage structure or a web structure 4 includes a number of steel beams which are anchored, preferably welded, to the internal cylindrical shell at a level below the top thereof. The ribs or beams have a large height relative to their width, and the attachment of the beams to shell 2 is of a predetermined strength that for an explosion of anticipated strength the beams will remain in position at one or both ends thereof. The number 5 designates a cover of light resolvable material which may be easily defibrated, for instance balsa wood or the like. The number 6 designates a plastics sheeting which functions as a moisture barrier and also as a ceiling or linear for the sand layer 7, which comprises finely divided, dry sand. In the spacing between the cylinders 2 and 3 is also positioned dry sand 8, and the entire building is preferably biased or supported on a sand bed having a binding layer, for instance asphalt, on top thereof. In a cold climate where frozen ground must be reckoned with, one may position a layer of insulation 9, l0 and 11, on the inside of the outer shell, on top of the sand layers and on the outside of the sand bed, respectively. As roof covering is preferably utilized a reinforced plastics sheeting or plastics film 12, which may be attached with an attaching means 13 along the circumferential edge of the outer cylinder shell. The sand layer 7 of the roof construction is shaped to be flush with the cylinder shells and is otherwise adapted such that the roof covering has a uniform slope towards the outer cylinder shell.

On top in the center of the roof covering is provided an air vent l4.

The wall construction is provided with a door opening structure in the shape of a tubular tunnel 17, which preferably is continually welded to the inner shell and outer shell, respectively, and along the bottom plate 1. A lower part of the inner shell is not cut away and forms a door sill 19. The door 15 itself is as shown shaped with a curvature conforming to the curvature of the inner shell and is preferably hinged such that it, when closed, overlaps the adjacent edges of the inner shell.

In pilot trials with detonation in a building as above described it has appeared that substantial savings in costs can be obtained by making the outer cylindrical shell from plates having a thickness of about one-third of the thickness necessary in the internal cylindrical shell. Using large plate thicknesses in the internal cylindrical shell, however, increases the danger that shearing fractures inthe internal shell will occur. This danger may be reduced by the replacement of one thick plate with two or more thinner plate shells to constitute the internal shell. The two or more thinner plate shells will be more easily deformed without breaking and will provide a larger ability to distribute the peak stresses resulting from the peak pressures of the detonation pressure wave. When selecting steel qualities one must furthermore observe the shear fragility of certain steel qualities at low temperatures. The insulating layers 9 and 10 will insulate and protect the internal shell construction against low temperatures and thus the danger for brittleness fractures in cold climatic environments.

FIG. 3 illustrates a modified embodiment of the rib structure in the roof construction of the building, Herein the separate rib elements 4 in the rib structure comprise steel section elements mounted in a pattern which can be compared with spokes excentrical relative to the centre of the shell and each of which are welded to the inside of the internal shell and at an angle directly to each other, respectively. Subject to an outwardly directed deformation of the inner shell, the'rib elements partly will be bent, partly twisted with comparatively little risk that the rib structure will be torn loose from the inner shell construction or be disintegrated in consequence of a detonation in the building.

What is claimed is:

l. A building structure for the storage or production of explosive materials, said building structure comprismg:

a floor plate;

an inner cylindrical metal shell rigidly attached at the bottom thereof to said floor plate;

an outer cylindrical metal shell rigidly attached at the bottom thereof to said floor plate, said outer shell being arranged coaxially around said inner shell with a cylindrical space between said inner and outer shells, said cylindrical space being filled with sand;

a rigid web roof supporting structure fixedly attached to said inner shell, the attachment of said web v structure to said inner shell being of sufiicient strength to prevent separation of said web structure from said inner shell upon the occurrence of an explosion of an anticipated strength of explosive material within said inner shell, said web structure having vertical extending openings therein for escape therethrough of explosive gas resulting from such explosion;

a cover positioned directly on top of said web structure;

a layer of sand positioned on top of said cover;

an outer roof covering positioned directly on top of said layer of sand; and

said cover and outer roof covering being formed of materials incapable of being broken into projectiles upon being lifted upwardly by an explosion within said inner shell.

2. A building structure as claimed in claim 1, wherein said cover is formed of a defibrated material.

3. A building structure as claimed in claim 1, wherein said inner shell is thicker than said outer shell.

4. A building structure as claimed in claim 3, wherein said inner shell comprises at least two concentric adjacent metal shell plate structures.

5. A building structure as claimed in claim 1, wherein the thickness of said layer of sand is greater than the radial thickness of said cylindrical space.

6. A building structure as claimed in claim 1, further comprising an insulating layer provided between said outer shell and said sand within said cylindrical space.

7. A building structure as claimed in claim 1, further comprising an insulating layer provided between said outer roof covering and said layer of sand.

8. A building structure as claimed in claim 1, further comprising a sand support bed positioned immediately below said floor plate, and an insulation layer positioned outwardly of said sand support bed.

9. A building structure as claimed in claim 1, wherein said outer roof covering extends outwardly of and overlaps said outer shell and is attached to said outer shell.

10. A building structure as claimed in claim 1, further comprising a sheet of moisture resistant material positioned between said cover and said layer of sand.

11. A building structure as claimed in claim 1, wherein said web structure comprises a plurality of horizontally extending metal elements, each attached at opposite ends thereof to said inner shell.

12. A building structure as claimed in claim 11, wherein said metal elements extend parallel to each other.

13. A building structure as claimed in claim 11, wherein said metal elements are mounted in a pattern to each extend eccentrically to the center of said inner shell, each of said metal elements being fixedly attached at the outer ends thereof to said inner shell and at the inner ends thereof to each other, whereby outward deformation of said inner shell will result in bending and twisting of said web structure.

14. A building structure as claimed in claim 1, wherein the upper surface of layer of sand is in the form of a cone centered about the longitudinal axis of said inner shell, said upper surface of said layer of sand being flush with the upper edge of said inner shell, and the upper surface of said sand in said cylindrical space slopes upwardly and inwardly at the same angle as said layer of sand, said outer roof covering having a continuous and equal slope from said longitudinal axis of said inner shell to said outer shell.

15. A building structure as claimed in claim 1, further comprising a tunnel-shaped opening extending through said inner shell and said outer shell, and a curved door positioned within said inner shell for selectively closing said opening. 

1. A building structure for the storage or production of explosive materials, said building structure comprising: a floor plate; an inner cylindrical metal shell rigidly attached at the bottom thereof to said floor plate; an outer cylindrical metal shell rigidly attached at the bottom thereof to said floor plate, said outer shell being arranged coaxially around said inner shell with a cylindrical space between said inner and outer shells, said cylindrical space being filled with sand; a rigid web roof supporting structure fixedly attached to said inner shell, the attachment of said web structure to said inner shell being of sufficient strength to prevent separation of said web structure from said inner shell upon the occurrence of an explosion of an anticipated strength of explosive material within said inner shell, said web structure having vertical extending openings therein for escape therethrough of explosive gas resulting from such explosion; a cover positioned directly on top of said web structure; a layer of sand positioned on top of said cover; an outer roof covering positioned directly on top of said layer of sand; and said cover and outer roof covering being formed of materials incapable of being broken into projectiles upon being lifted upwardly by an explosion within said inner shell.
 2. A building structure as claimed in claim 1, wherein said cover is formed of a defibrated material.
 3. A building structure as claimed in claim 1, wherein said inner shell is thicker than said outer shell.
 4. A building structure as claimed in claim 3, wherein said inner shell comprises at least two concentric adjacent metal shell plate structures.
 5. A building structure as claimed in claim 1, wherein the thickness of said layer of sand is greater than the radial thickness of said cylindrical space.
 6. A building structure as claimed in claim 1, further comprising an insulating layer provided between said outer shell and said sand within said cylindrical space.
 7. A building structure as claimed in claim 1, further comprising an insulating layer provided between said outer roof covering and said layer of sand.
 8. A building structure as claimed in claim 1, further comprising a sand support bed positioned immediately below said floor plate, and an insulation layer positioned outwardly of said sand support bed.
 9. A building structure as claimed in claim 1, wherein said outer roof covering extends outwardly of and overlaps said outer shell and is attachEd to said outer shell.
 10. A building structure as claimed in claim 1, further comprising a sheet of moisture resistant material positioned between said cover and said layer of sand.
 11. A building structure as claimed in claim 1, wherein said web structure comprises a plurality of horizontally extending metal elements, each attached at opposite ends thereof to said inner shell.
 12. A building structure as claimed in claim 11, wherein said metal elements extend parallel to each other.
 13. A building structure as claimed in claim 11, wherein said metal elements are mounted in a pattern to each extend eccentrically to the center of said inner shell, each of said metal elements being fixedly attached at the outer ends thereof to said inner shell and at the inner ends thereof to each other, whereby outward deformation of said inner shell will result in bending and twisting of said web structure.
 14. A building structure as claimed in claim 1, wherein the upper surface of layer of sand is in the form of a cone centered about the longitudinal axis of said inner shell, said upper surface of said layer of sand being flush with the upper edge of said inner shell, and the upper surface of said sand in said cylindrical space slopes upwardly and inwardly at the same angle as said layer of sand, said outer roof covering having a continuous and equal slope from said longitudinal axis of said inner shell to said outer shell.
 15. A building structure as claimed in claim 1, further comprising a tunnel-shaped opening extending through said inner shell and said outer shell, and a curved door positioned within said inner shell for selectively closing said opening. 